British broadcaster David Frost, a master of the television interview, famed for coaxing an apology for Watergate from Richard Nixon, has died suddenly, his family said on Sunday.

Aged 74, he had a heart attack late on Saturday aboard a luxury cruise liner where he had a speaking engagement. His sudden death brought tributes from international celebrities and political leaders, many of whom called him a good friend as well as an acute interrogator.

"David Frost died of a heart attack last night aboard the Queen Elizabeth, where he was giving a speech," his family said in a statement, adding they were "devastated".

The ship's website indicated the liner left the southern English port of Southampton on Saturday, bound for Lisbon.

A household name in Britain since 1962, when as a recent Cambridge graduate he hosted the cutting edge television satire show "That Was The Week That Was", Frost secured his broader reputation with the Nixon interviews of 1977, three years after the president retreated into silence after quitting in disgrace.

In those encounters, dramatised in the 2008 film "Frost/Nixon", the British talk-show host sparred with the former US president for hours before eliciting a moment of historical drama - Nixon apologised for the bugging of Democratic rivals at Washington's Watergate building and the later cover-up.

David Frost with former president Richard Nixon. AP file photo

"I'm sorry," Nixon finally confessed to Frost. "I let down my friends. I let down the country. I let down our system of government and the dreams of all those young people that ought to get into government but will think it is all too corrupt."

Frost, the son of a Methodist minister from Kent outside London, launched his career while still at Cambridge University as a leading figure in the Footlights Dramatic Club, a hotbed of innovative comedy that also produced members of Monty Python.

Speaking for a generation that grew up in a Britain shorn of its imperial power - if not pretensions - after World War Two, "That Was The Week That Was" mocked an indignant establishment, enjoying huge ratings and making the youthful Frost a star.

He went on to become best known as an interviewer of world leaders, sitting opposite virtually every US president and British prime minister of the age. He showed a rare talent for extracting intriguing and revealing information.

An engaging personality off-screen, and made wealthy by his interests in a string of successful television ventures, Frost's celebrity-studded contact book - and his lavish parties - were the stuff of legend in politics and showbusiness.

That his own style and a catchphrase became themselves much mimicked only underlined his status as a fixture on the small screen. He continued to pursue the art of the interview, presenting a weekly conversation on Al Jazeera International.

His recent guests included Israeli President Shimon Peres and British racing driver Lewis Hamilton.

BAFTA presenters actor Michael Sheen and David Frost at the Royal Opera House in central London. AFP file photo

British Prime Minister David Cameron spoke for many with his comment on Twitter: "He made a huge impact on television and politics. The Nixon interviews were among the great broadcast moments - but there were many other brilliant interviews.

"He could be - and certainly was with me - both a friend and a fearsome interviewer."